The Indian Space Research Organisation (ISRO) successfully conducted a sea-level hot test of the CE20 cryogenic engine at the ISRO Propulsion Complex Mahendragiri, Tamil Nadu. During the test, the engine operated for 165 seconds and generated about 22 tonnes of thrust, demonstrating an enhanced thrust capability aimed at improving the performance of India’s heavy-lift rocket LVM3.
The upgraded thrust capability will enable higher payload capacity for future satellite launches and human spaceflight missions.
CE20 Cryogenic Engine
| Feature | Details |
| Engine Name | CE20 Cryogenic Engine |
| Developed By | Indian Space Research Organisation |
| Test Location | ISRO Propulsion Complex, Mahendragiri (Tamil Nadu) |
| Test Duration | 165 seconds |
| Test Type | Sea-level hot test |
| Thrust Achieved | ~22 tonnes |
| Used In | Upper stage of LVM3 launch vehicle |
Key Points
- CE20 is an indigenously developed cryogenic rocket engine.
- It powers the upper cryogenic stage of LVM3, India’s heaviest operational launch vehicle.
- The engine has been human-rated for the Gaganyaan Programme.
Purpose of Test
The ground test was conducted to validate an upgraded configuration of the CE20 engine.
Objective
- Increase thrust capability to 22 tonnes
- Improve payload carrying capacity of LVM3
- Support future heavy satellite launches and deep-space missions
- Strengthen human spaceflight capability for Gaganyaan
Future missions of LVM3 are planned to operate with an uprated C32 cryogenic stage, powered by the higher-thrust CE20 engine.
Technical Aspects of the Test
- The sea-level hot test using Nozzle Protection System (NPS) evaluated the engine’s performance under challenging conditions.
- The test also qualified the flight acceptance process for engines operating at higher thrust levels.
Challenges in Sea-Level Testing
Testing cryogenic engines at sea level is technically complex due to:
- High area ratio nozzle
- Very low exit pressure (~50 mbar)
- Risk of flow separation inside the nozzle
Flow separation can cause:
- Severe vibrations
- Thermal stresses
- Potential mechanical damage to the nozzle
Despite these challenges, engine performance and test facility operations remained stable throughout the test.
Cryogenic Engine: Concept
A cryogenic engine is a rocket engine that uses liquefied gases stored at extremely low temperatures (below −150°C) as propellants.
Common Propellants Used
| Propellant | Role |
| Liquid Hydrogen (LH₂) | Fuel |
| Liquid Oxygen (LOX) | Oxidizer |
These fuels combine in the combustion chamber to produce high-velocity exhaust gases, generating thrust according to Newton’s Third Law of Motion.
Advantages of Cryogenic Engines
- Higher Efficiency
- Produce greater thrust per kilogram of fuel.
- Environmentally Safer
- Non-toxic and non-corrosive propellants.
- Operational Safety
- Non-hypergolic fuels reduce risk during ground handling.
- Cost Effectiveness
- Greater efficiency reduces overall launch cost.
Disadvantages
- Complex Storage Systems
- Requires special infrastructure to maintain ultra-low temperatures.
- Ignition Complexity
- Needs sophisticated ignition mechanisms.
Countries with Cryogenic Engine Technology
Only six countries possess indigenous cryogenic rocket technology:
- United States
- Russia
- Japan
- France
- China
- India
This makes cryogenic propulsion a strategically significant and technologically advanced capability.
Significance for India’s Space Programme
- Enhances payload capacity of LVM3 rockets.
- Supports future deep-space missions and heavy satellite launches.
- Critical for human spaceflight under the Gaganyaan mission.
- Strengthens India’s self-reliance in advanced rocket propulsion technologies.
- Positions India among elite nations with cryogenic launch capability.